Select the range of supposed email addresses and use F&R, Regular expression enabled with Current selection only.
^[^@]+$ in the field behind “Find:”, the order
(RegEx can also “search negative”. If you need to understand, study Regular Expression Tutorial - Learn How to Use Regular Expressions, The
+ in place of the
* used by @JohnSUN avoids to find empty cells.)
For what you need to do, filtering might be the better means:
Select the column containing the email addresses, go
>Data>More Filters>Standard Filter The dialog that opens will offer the variant
Does not contain under Condition, and you only need to enter the
@ then under Value.